The present invention relates generally to agricultural equipment, and more specifically to a field tracking control system for controlling a header position of an agricultural harvester.
To harvest crops, agricultural harvesters such as combines and forage harvesters utilize a header that contains a cutting mechanism. The cutting mechanism cuts the crops and the header channels the crops to a feeder. The header attaches onto the feeder which conveys the crops to the harvester. A feeder adapter connects the header to the feeder which couples to the harvester. To laterally tilt the feeder left to right, a field tracking cylinder is mechanically attached between the feeder and the feeder adapter. The field tracking cylinder extends and retracts, typically due to hydraulics, to tilt the feeder adapter, which in turn tilts the header relative to a frame of the harvester and to the ground.
To control the position of the header during operation of the harvester, some harvesters employ a control system, such as the Field Tracker(copyright) control system manufactured by the Hart Carter Corporation (HCC). Control systems offer both automatic and manual mode operations to give an operator flexibility in operating the equipment.
Operation in the automatic mode allows the header to automatically tilt side to side, independently of the harvester, to closely follow a ground contour which may be uneven or sloped. In the automatic mode, the header is lowered close to the ground to harvest short crops, such as soybeans. As the harvester moves forward, the header is automatically tilted side to side to follow the ground contour. At the end of each run, the header is raised so that the harvester may be rapidly driven and positioned at the next row. When raised, the header is automatically leveled with the harvester. After the harvester is turned around, the header is again lowered to start the next run.
Manual mode operation, on the other hand, allows the operator to position the header higher to harvest taller crops. In the manual mode, the operator manually controls the angle of the header relative to the harvester to follow the contours of the ground. At the end of each run, the header is raised but not automatically leveled with the harvester. Therefore, when the header is raised at the end of the run, the header may be at an angle with respect to the harvester.
A problem exists in that the operator must manually level the header to the harvester before starting a next run. The operator, who is in the cab of the harvester, cannot easily determine when the header is level to the harvester. Therefore, the operator is not assured that the header is in a known position for transport and for resuming harvesting.
Accordingly, it is a primary object of the present invention to provide an improved field tracking control system.
It is another object to provide a field tracking control system which obtains automatic centering of the harvester""s header when the header is lifted when harvesting in a manual mode.
It is still another object to provide a control system with a manual/auto-center mode which allows an operator to manually control the angle of the header to conform to the terrain, and at the end of each run automatically level the header to the harvester when the header is raised.
Other objects and advantages will become apparent upon reading the following detailed description, in conjunction with the attached drawings.
Generally, a field tracking control system for controlling a header of an agricultural harvester provides operation in both manual and automatic modes. In addition, the field tracking control system provides automatic leveling of the header, even when in the manual harvesting mode.
In one aspect of the invention a field tracking control system includes a header tilt control module to control a feeder""s lateral tilt. A self centering operation of the header tilt control module is activated when the harvester is operated in the automatic or the manual/auto-center modes and the feeder is raised above a predetermined height. In the manual/auto-center mode, a feeder housing limit switch is used to activate the self centering operation of the header tilt control module. During the self centering operation, the header tilt control module compares a self-centering signal and a fixed signal to determine when the header is level relative to the frame of the harvester. If the feeder is not level to the harvester, the header tilt control module operates to automatically level the feeder to the harvester""s frame.